This invention relates to electronic control systems for household appliances and, more particularly, to such systems for sensing and correcting load imbalances in a washing machine and aborting a machine cycle if the imbalance cannot be corrected.
Unbalanced loads in washing machines cause excessive mechanical and electrical stresses. It is thus important to be able to sense when an unbalanced load condition exists and to correct it. Sensing of load balance using either mechanical or solid state sensors (load cells, for example) is costly and reduces system reliability. Load balance can also be detected directly by sensing the motor/drum speed of the machine, but this requires costly tachogenerators. In addition, most sensing techniques require extra electrical leads either to the motor or to the rest of the system, which reduces both the reliability and cost-effectiveness of the system.